Pretty easy...open an image and make sure ALL settings are set to Default (which will be PV 2012), then without changing ANY other settings (unless you want those in your new Default), go to the Camera Calibration panel and change the PV to 2010. This will change the settings to line up to all of the PV 2010 controls. Then go to the ACR flyout menu and select Save New Camera Raw Defaults...

Note, you'll need to do this for each camera model you use because the Defaults are tied to the specific model of camera by XMP metadata. Also, if you decide to change your mind, you can go to the same flyout menu and select Reset Camera Raw Defaults to go back to the original Adobe standards...

Save New Camera Raw Defaults did not work for me either. After launching ACR via Photoshop CS6, I changed Process to 2010, Camera Profile to Camera Neutral, and saved it as the ACR default. After relaunching ACR, Camera Profile defaulted to Camera Neutral, but Process reverted back to 2012.

My suspicion is that Adobe is passive-aggressively attempting to force migration to Process 2012. With ACR CS5, a previously unedited RAW image defaults to Process: "2010 (current)", with 2012 listed as an option. With ACR CS6, the same unedited RAW image file defaults to Process: "2012 (current)", with 2010 listed as an option. Evidently, the "(current)" label has nothing to do with the file's metadata; it indicates which Process that version of ACR will use as its default.

So to answer the OP's question, the only way I can see to have ACR default to Process 2010 is to launch Photoshop CS5...

My suspicion is that Adobe is passive-aggressively attempting to force migration to Process 2012.

Uh no...you don't understand Process Versions...if an image has been touched by a previous process version then the process version in place with the settings will be honored...PV 2012 will ONLY be defaulted to if the image has never been touched by ACR/LR.

If you want PV 2010 by default, I've already explained how to do that. If you don't know how to do that, it would be useful to explain EXACTLY what you tried to do...the odds are really good the problem is user error.

Well I'm finding exactly the same thing. If you set a camera raw default with process 2010 then it doesn't stick. Take brand new raw file. Change to process 2010 then apply usual defaults to taste. Choose 'save new camera raw defaults' in dropdown. Exit file with 'done' button. Open different brand new raw file from same camera. Process is 2012 and there has been an automatic conversion of all the other changes to fit with the 2012 toolset. What are we doing wrong here?

Uh no...you don't understand Process Versions...if an image has been touched by a previous process version then the process version in place with the settings will be honored...PV 2012 will ONLY be defaulted to if the image has never been touched by ACR/LR.

Yes, that's exactly what I reported in my post above. I tested ACR CS5 and ACR CS6 on previously unedited RAW files that had no associated sidecar files. If I had instead used previously edited files, both CS5 and CS6 versions of ACR would have respected the previously selected Process Version, as you pointed out.

What Ben and I are not allowed to do is to set ACR CS6's default Process Version for previously unedited RAW files to PV 2010. Was it indeed an intentional decision by Adobe to exclude this setting from the Save New Camera Raw Defaults function, in order to hard code that default to PV 2012 in ACR CS6?

Uh no...you don't understand Process Versions...if an image has been touched by a previous process version then the process version in place with the settings will be honored...PV 2012 will ONLY be defaulted to if the image has never been touched by ACR/LR.

If you want PV 2010 by default, I've already explained how to do that. If you don't know how to do that, it would be useful to explain EXACTLY what you tried to do...the odds are really good the problem is user error.

Jeff,

Have you actually tried that? I followed your instructions exactly on my Win8 ACR setup and found, like the OP, that the PV2010 setting does not hold even though other settings do. Since ACR does not alter the raw file and the file specific data are stored in the sidecar files, merely deleting the sidecar file should be sufficient to restore the raw file to its virgin state.

One could ask, where are these preferences stored? Not in the raw file itself, but in the ACR code? I would think that they would be stored in the registry for windows ACR and likely in its equivalent for the Mac. Shown below are the data in the registry for ACR 7. I would imagine that the defaults are in there somewhere and the process version is not included and ACR uses PV2012 by default. Perhaps this is a question for Eric Chan to resolve.

Well, Eric resolved the issue...from Eric "Pretty sure that PV 2012 is always the default even when trying to customize per-camera defaults."

So, I was wrong about being able to include the Process Version in the Camera Raw Defaults, sorry...you can't. Best you can do is save out a Preset with PV 2010 as the only subsetting and from Bridge you can select all and use the Edit menu>Develop Settings and select your PV 2010 preset. I know for a fact that this works because I just tested it :~)

Turns out this default Process Version behaviour wasn't introduced in ACR v7/CS6, but was actually inherited from ACR v6. If you launch an unedited RAW file in Photoshop CS5, ACR 6 will default to PV 2010(current), just as CS6 defaults to PV2012(current). And in both cases, switching to a different process will provoke ACR to display a "!" button at the bottom right of the image, prompting you to switch back to the (current) process.

My hunch is this default behavior was originally intended to remind users to upgrade older photos from the original PV 2003 to PV 2010, at the time it was introduced a few years ago. That, however, was a less controversial upgrade since it left the controls unchanged. With PV 2012, upgrading involves a significant change in user interface and slider functionality. Hopefully, Adobe will revise the upcoming CS7 version of ACR to allow users to set their own preferred Process Version in the saved default settings.

What don't you like about the highlights with PV2012? Are you finding it impossible to achieve the same look with the PV2012 controls and save those (PV2012) settings as a default?

I like PV2012 fine for clients who want quickly processed results they can post on FaceBook. For images that are worth putting time into, I prefer to start with flat contrast in PV2010 and adjust the tone curves manually. It's similar to setting light exposure and lens focus - in some situations auto-exposure and/or auto-focus may be perfectly appropriate, while other cases require full manual control.

Has anyone found a resolution for this issue? I recently upgraded to Camera Raw 7 and also prefer the Process 2010 sliders, but as others have commented the "Process" box under "Camera Calibration" is not saved as part of the "Save new Camera Raw defaults" option. The best solution I've found is to change the "Process" to 2010 in one file then copy & paste those settings to all files in the folder before starting work on them, but it would be nice to be able to avoid this step.